Precise Measurement of the Neutron Magnetic Form Factor $G_M^n$ in the Few-${\mathrm{GeV}}^2$ Region

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range $Q^2=1.0–4.8{\mathrm{GeV}}^2$ with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

Figure 1

Results for $R$ as a function of $Q^2$ for two beam energies. Each set is a weighted sum of the TOF and EC neutron measurements. Only statistical uncertainties are shown. Numerical results are reported in the CLAS Physics Data Base [20].

Figure 2

Results for $G_M^n/({\mu }_n{G}_D)$ as a function of $Q^2$ for four different measurements (two beam energies). Only statistical uncertainties are shown.

Figure 3

Results for $G_M^n/({\mu }_n{G}_D)$ from the CLAS measurement are compared with a selection of previous data [10, 11, 26, 27, 28, 29] and theoretical calculations [3, 4, 5]. Numerical results are reported in the CLAS Physics Data Base [20].